Login via SSH and execute the following command to force all froxlor conjobs.
Helpful for some fast changes or if you just can't wait.
/usr/bin/php5 /var/www/froxlor/scripts/froxlor_master_cronjob.php --force
If something went wrong just wait for the regular conjob. If that does not work either, try to find the configuration instructions in Froxlor and validate the settings of your system:
Configuration -> choose Distribution -> Misc (System) -> Crond (cronscript)